Method for fabricating a gate dielectric layer

Abstract

A method for fabricating the gate dielectric layer comprises forming a high-k dielectric layer over a substrate; forming an oxygen-containing layer on the high-k dielectric layer by an atomic layer deposition process; and performing an inert plasma treatment on the oxygen-containing layer.

What is claimed is: 
     
       1. A method for fabricating a high-k dielectric layer, comprising:
 forming a high-k dielectric layer over a substrate; 
 forming an oxygen-containing layer without metallic element on the high-k dielectric layer by an atomic layer deposition process; and 
 performing an inert plasma treatment on the oxygen-containing layer to drive oxygen radicals into the high-k dielectric layer for filling vacancies and replacing impurities therein. 
 
     
     
       2. The method of  claim 1 , wherein the atomic layer deposition process comprises a sequence of ALD cycles. 
     
     
       3. The method of  claim 1 , wherein the step of forming a high-k dielectric layer over a substrate is performed using an atomic layer deposition process. 
     
     
       4. The method of  claim 1 , wherein the step of forming a high-k dielectric layer comprises forming the high-k dielectric layer with a thickness of between about 1 nm and about 4 nm. 
     
     
       5. The method of  claim 1 , wherein an oxygen source chemical of the oxygen-containing layer comprises a material selected from the group consisting of O 2 , O 3 , H 2 O, and H 2 O 2 . 
     
     
       6. The method of  claim 1 , wherein the steps of forming a high-k dielectric layer over a substrate and forming an oxygen-containing layer on the high-k dielectric layer by an atomic layer deposition process are performed using different oxygen source chemicals. 
     
     
       7. The method of  claim 1 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed using at least one of N 2 , Ar, or He as a source gas. 
     
     
       8. The method of  claim 1 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed under a source power of between about 20 W and 500 W. 
     
     
       9. The method of  claim 1 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed under a pressure of between about 100 mTorr and 10 Torr. 
     
     
       10. A method for fabricating a gate dielectric layer in a semiconductor device, comprising:
 forming a hafnium oxide layer as the gate dielectric layer over a substrate by a first atomic layer deposition process; 
 forming an oxygen-containing layer without metallic element on the hafnium oxide layer by a second atomic layer deposition process; and 
 performing an inert plasma treatment on the oxygen-containing layer to drive oxygen radicals into the hafnium oxide layer for filling vacancies and replacing impurities therein. 
 
     
     
       11. The method of  claim 10 , wherein a hafnium source chemical of the first atomic layer deposition process is selected from the group consisting of HfCl4, TEMAH (tetra-ethyl-methyl amino hafnium) or Hf(MMP) 4  [tetra(1-methoxy-2-methyl2-propoxy)Hf]. 
     
     
       12. The method of  claim 10 , wherein an oxygen source chemical of the first atomic layer deposition process is selected from the group consisting of O 2 , O 3 , H 2 O, and H 2 O 2 . 
     
     
       13. The method of  claim 10 , wherein the step of forming a hafnium oxide layer comprises forming the hafnium oxide layer with a thickness of between about 1 nm and about 4 nm. 
     
     
       14. The method of  claim 10 , wherein the first atomic layer deposition process comprises a sequence of ALD cycles. 
     
     
       15. The method of  claim 10 , wherein the second atomic layer deposition process comprises a sequence of ALD cycles. 
     
     
       16. The method of  claim 10 , wherein the first atomic layer deposition process and the second atomic layer deposition process are performed using different oxygen source chemicals. 
     
     
       17. The method of  claim 10 , wherein an oxygen source chemical of the oxygen-containing layer comprises a material selected from the group consisting of O 2 , O 3 , H 2 O and H 2 O 2 . 
     
     
       18. The method of  claim 10 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed using N2, Ar, or He as a source gas. 
     
     
       19. The method of  claim 10 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed under a source power of between about 20 and 500 W. 
     
     
       20. The method of  claim 10 , wherein the step of performing an inert plasma treatment on the oxygen-containing layer is performed under a pressure of between about 100 mTorr and 10 Torr.